Suspected members of the Nigerian Islamist sect Boko Haram raided the north-eastern town of Bama on Tuesday, leaving 55 people dead, the military said on Tuesday.

Boko Haram gunmen killed 22 police officers, 14 prison officials, two soldiers and four civilians, while 13 of the group's own members died, military spokesman Sagir Musa told Reuters.

Gunmen freed 105 prison members during the raid which began at around 5 a.m. (5:00 a.m. British time) and lasted almost five hours, Musa said. Bama's police station, military barracks and government buildings were burned to the ground, a Reuters witness saw.

Bama is a small, remote town in north-eastern Borno state, where Boko Haram first launched an uprising in 2009.